Chronic alcohol ingestion has long been known to cause protean effects on the human immune system. The applicant and others have shown that there are increases in CD8+ lymphocyte activation markers and substantial modulation in fine T lymphocytes subsets in alcoholic patients. Because the human immunodeficiency virus type 1 (HIV) utilizes the CD4 molecule as its receptor, and HIV replication is regulated extensively by T cell activation and cytokine modulation, it is important to determine the effects of alcohol on HIV replication. Anecdotal reports and poorly controlled studies suggest that alcohol ingestion increases the ability of HIV to infect susceptible cells, and also increases HIV replication in previously infected cells. Unfortunately, there are no definitive data which demonstrate that alcohol consumption has an overall significant effect on HIV infected individuals. Therefore, the applicants believe that the most basic issue in alcohol-HIV research is whether or not alcohol consumption enhances HIV infection or disease progression. Currently, determination of the plasma HIV RNA levels combined with the CD4+ T cell number provides the best prediction of HIV disease progression in a given individual. Consequently, the applicants propose to measure HIV RNA levels, CD4+ T cell numbers and T cell activation markers in HIV infected people before, during and following controlled alcohol consumption. The results of these studies will characterize the effects of alcohol consumption on HIV replication, CD4 T cell number and activation in HIV infected people. This information is critical to furthering the understanding of the complex interactions of alcohol use, human T cells and HIV disease.